summarise_all: Summarise and mutate multiple columns.

In sctyner/dplyr050: A Grammar of Data Manipulation

Description

summarise_all() and mutate_all() apply the functions to all (non-grouping) columns. summarise_at() and mutate_at() allow you to select columns using the same name-based select_helpers as with select(). summarise_if() and mutate_if() operate on columns for which a predicate returns TRUE. Finally, summarise_each() and mutate_each() are older variants that will be deprecated in the future.

Usage

summarise_all(.tbl, .funs, ...)

mutate_all(.tbl, .funs, ...)

summarise_if(.tbl, .predicate, .funs, ...)

mutate_if(.tbl, .predicate, .funs, ...)

summarise_at(.tbl, .cols, .funs, ...)

mutate_at(.tbl, .cols, .funs, ...)

summarize_all(.tbl, .funs, ...)

summarize_at(.tbl, .cols, .funs, ...)

summarize_if(.tbl, .predicate, .funs, ...)

Arguments

.tbl	a tbl
.funs	List of function calls generated by funs(), or a character vector of function names, or simply a function (only for local sources).
...	Additional arguments for the function calls. These are evaluated only once.
.predicate	A predicate function to be applied to the columns or a logical vector. The columns for which .predicate is or returns TRUE will be summarised or mutated.
.cols	A list of columns generated by vars(), or a character vector of column names, or a numeric vector of column positions.

Value

A data frame. By default, the newly created columns have the shortest names needed to distinguish the output. To force inclusion of a name, even when not needed, name the input (see examples for details).

See Also

vars(), funs()

Examples

by_species <- iris %>% group_by(Species)

# One function
by_species %>% summarise_all(n_distinct)
by_species %>% summarise_all(mean)

# Use the _at and _if variants for conditional mapping.
by_species %>% summarise_if(is.numeric, mean)

# summarise_at() can use select() helpers with the vars() function:
by_species %>% summarise_at(vars(Petal.Width), mean)
by_species %>% summarise_at(vars(matches("Width")), mean)

# You can also specify columns with column names or column positions:
by_species %>% summarise_at(c("Sepal.Width", "Petal.Width"), mean)
by_species %>% summarise_at(c(1, 3), mean)

# You can provide additional arguments. Those are evaluated only once:
by_species %>% summarise_all(mean, trim = 1)
by_species %>% summarise_at(vars(Petal.Width), mean, trim = 1)

# You can provide an expression or multiple functions with the funs() helper.
by_species %>% mutate_all(funs(. * 0.4))
by_species %>% summarise_all(funs(min, max))
# Note that output variable name must now include function name, in order to
# keep things distinct.

# Function names will be included if .funs has names or whenever multiple
# functions are used.
by_species %>% mutate_all(funs("in" = . / 2.54))
by_species %>% mutate_all(funs(rg = diff(range(.))))
by_species %>% summarise_all(funs(med = median))
by_species %>% summarise_all(funs(Q3 = quantile), probs = 0.75)
by_species %>% summarise_all(c("min", "max"))

# Two functions, continued
by_species %>% summarise_at(vars(Petal.Width, Sepal.Width), funs(min, max))
by_species %>% summarise_at(vars(matches("Width")), funs(min, max))

sctyner/dplyr050 documentation built on May 17, 2019, 2:22 p.m.